31323661 has 4 divisors (see below), whose sum is σ = 31570432. Its totient is φ = 31076892.

The previous prime is 31323641. The next prime is 31323703. The reversal of 31323661 is 16632313.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16632313 = 47 ⋅353879.

It is a cyclic number.

It is not a de Polignac number, because 31323661 - 2⁵ = 31323629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31323641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123195 + ... + 123448.

It is an arithmetic number, because the mean of its divisors is an integer number (7892608).

Almost surely, 2^31323661 is an apocalyptic number.

It is an amenable number.

31323661 is a deficient number, since it is larger than the sum of its proper divisors (246771).

31323661 is a wasteful number, since it uses less digits than its factorization.

31323661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246770.

The product of its digits is 1944, while the sum is 25.

The square root of 31323661 is about 5596.7545059615. The cubic root of 31323661 is about 315.2275537262.

Adding to 31323661 its reverse (16632313), we get a palindrome (47955974).

The spelling of 31323661 in words is "thirty-one million, three hundred twenty-three thousand, six hundred sixty-one".